Puncture locating system with blood pulsation indicator

ABSTRACT

Disclosed are puncture sealing systems and methods of locating a puncture site within a vessel. The systems can include elongated dilators and access sheaths that are configured to locate the puncture site within a vessel so that the position of the puncture site relative to a distal end of the access sheath is known during a puncture sealing procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No. 16/279,577, filed on Feb. 19, 2019, the entire disclosure of which is incorporated by reference into the present application.

TECHNICAL FIELD

The present application relates to a puncture locating system and method, and in particular, to a puncture location system utilizing a flexible member to indicate blood pulsations.

BACKGROUND

During the use of vascular closure systems after vascular interventions, it is often important to know the location of a puncture in the vessel, and in particular, providing for exact placement of vascular sheaths. Typically, a “blood flashback” method is used to position a vascular device.

SUMMARY

An embodiment of the present disclosure includes a puncture locating device for locating a puncture in a blood vessel. The puncture locating device includes an elongated dilator having a distal end, a proximal end that is opposite the distal end, an outer surface, an internal channel that extends from the distal end to the proximal end, an inlet opening that is open to the internal channel and is spaced from the distal end, and an outlet opening disposed between the proximal end and the inlet opening. The dilator also includes a flexible barrier attached to the elongated dilator and overlying the outlet opening so that the flexible barrier and the outer surface proximate the outlet opening at least partially define an internal volume. When the elongated dilator is inserted into the puncture of the blood vessel, blood flows into the inlet opening through the channel and out the outlet opening into the internal volume, such that, pulsations in the blood flow cause the flexible barrier to pulse, thereby generating a visual and tactile indication of presence of the inlet opening in the blood vessel.

Another embodiment of the present disclosure includes a puncture locating device for locating a puncture in a blood vessel. The puncture locating device includes an elongated dilator having a distal end, a proximal end that is opposite the distal end, an outer surface, an internal channel that extends from the distal end to the proximal end, an inlet opening that is open to the internal channel and is spaced from the distal end, an outlet opening disposed between the proximal end and the inlet opening. The puncture locating device includes a blood pulsation indicator overlying the outlet opening so that the blood pulsation indicator and the outer surface proximate the outlet opening at least partially define an internal volume. When the elongated dilator is inserted into the puncture of the blood vessel, blood flows into the inlet opening through the outlet opening into the internal volume, such that, pulsations in the blood flow cause the blood pulsation indicator to pulse, thereby generating a visual and tactile indication of presence of the inlet opening in the blood vessel.

An embodiment of the present disclosure includes a method for locating a puncture in a blood vessel of a patient. The method includes inserting a guidewire through the puncture into the vessel so that a distal end of the guidewire is inside the vessel and the guidewire extends out of the puncture. The method also includes inserting a proximal end of the guidewire into a distal end of a dilator, the dilator including a proximal end spaced from the distal end, and a plurality of markings along an outer surface of the dilator. The method also includes moving the dilator along the guidewire in a distal direction until blood in the blood vessel flows through an inlet opening of the dilator and into an internal volume at least partially defined by the outer surface of the dilator and a flexible barrier attached to the dilator, whereby the flexible barrier repeatedly pulses in response to pressure pulsations of blood in the blood vessel. The method also includes retracting the dilator in a proximal direction along the guidewire until the flexible barrier no longer pulses. The method also includes noting a marking of the plurality of markings on the dilator that is adjacent to the surface of the patient's skin when flexible barrier no longer pulses. This, in turn, provides an indication of a depth at which the puncture is present.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of example embodiments of the application, will be better understood when read in conjunction with the appended drawings, in which there is shown in the drawings example embodiments for the purposes of illustration. It should be understood, however, that the application is not limited to the precise systems and methods shown. In the drawings:

FIG. 1 is a top plan view of a puncture location system including a elongated dilator and an access sheath according to an embodiment of the present disclosure;

FIG. 2 is a top plan view of the elongated dilator shown in FIG. 1;

FIG. 3 is a side view of the elongated dilator shown in FIG. 2;

FIG. 4 is a cross-sectional view of the locating dilator taken along line 3-3 in FIG. 2;

FIG. 5 is a cross-sectional view of the elongated dilator take along line 5-5 in

FIG. 2;

FIG. 6 is a top plan view of the access sheath of the puncture sealing system shown in FIG. 1;

FIG. 7 is a schematic showing the elongated dilator of FIG. 1 positioned so the distal end of the dilator is disposed within a vessel and a blood intel hole is outside the vessel;

FIG. 8 is a schematic showing the elongated dilator of FIG. 1 positioned such that the inlet hole is disposed within a vessel proximate to a vessel puncture and blood pressure in the vessel causing the puncture indicator to pulsate;

FIG. 9 is a schematic showing the elongated dilator of FIG. 1 retracted from the position shown in FIG. 8 such that the inlet hole is located at the vessel puncture;

FIG. 10 is a schematic showing the access sheath of FIG. 1 being moved into the vessel along the guidewire; and

FIG. 11 is a schematic showing the access sheath removed from the access channel and the sheath body positioned such that a depth marking on the sheath body that corresponds to the at least one marking on the elongated dilator is visible above the surface of the skin.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “proximally” and “distally” refer to directions toward and away from, respectively, the individual operating the system. The terminology includes the above-listed words, derivatives thereof and words of similar import.

Referring to FIG. 1, a puncture locating system 2 includes an elongated dilator 10 and an access sheath 118 used in locating a puncture in a vessel during or along with an interventional cardiovascular procedure. Typically, before an interventional cardiovascular procedure, a puncture may be made in the femoral artery. In one example, a vascular closure device composed of an absorbable anchor, a folding sealing plug, a suture and a downward locking member have been developed and may be used to seal these punctures. However, before sealing can occur the depth at which the device needs to be inserted must be attained. Currently, the procedure is conducted with a puncture locator comprising of two inlet holes towards the distal end and one outlet opening at the proximal end. Conventional puncture locators allow blood to flow through the dilator and out an outlet opening when the inlet hole is present within the circulatory tract. The present disclosure, however, includes embodiments of puncture location system comprising an elongated dilator 10 with a blood pulsation indicator 50, as will be further explained below.

Referring to FIGS. 2-5, the elongated dilator 10 is configured to locate a puncture site 12 (FIGS. 7-9) in a vessel 13 with the blood pulsation indicator 50. The elongated dilator 10 includes a dilator body 34 that is elongated along a central longitudinal axis A in a first direction L. The first direction may be referred to as a longitudinal direction in this disclosure. The dilator body 34 defines a proximal end 35 p and a distal end 35 d that is spaced from the proximal end 35 p along the first direction L. The distal end 35 d of the dilator may be tapered to facilitate entry into the vessel. The dilator body further defines an inner surface 37, which may define an internal guide channel 38, and an outer surface 39 (FIG. 5). The elongated dilator 10 is configured to be moved along a guidewire 14 toward the puncture site 12 such that the elongated dilator 10 enters the vessel 13 through the puncture site 12. As the elongated dilator 10 enters the vessel 13 the elongated dilator 10 dilates the puncture site 12.

The elongated dilator is sized for a range of procedures. In one embodiment, the outer surface 39 defines an outer cross-sectional dimension that is substantially perpendicular to the central longitudinal axis A and the outer cross-sectional dimension is at least about 2.50 mm. In one example, the outer cross-sectional dimension is at least about 2.50-5.0 mm. However, dimensions outside of this range are possible.

Referring to FIG. 5, the internal guide channel 38 that extends through the dilator body 34 along the first direction L from the distal end 35 d through to the proximal end 35 p. The internal guide channel 38 is configured to receive the guidewire 14 such that the elongated dilator 10 can be moved along the guidewire 14 toward the puncture site 12. The internal guide channel 38 at the distal end 35 d and proximal end 35 p can have a diameter that is substantially equal to that of the guidewire 14 so that the elongated dilator 10 can move along the guidewire 14 in a controlled manner.

Referring to FIGS. 2-5, the dilator 10 can further define a blood inlet hole 42 and a blood outlet opening 46. The blood inlet hole 42 that extends through the dilator body 34 along a direction that is transverse to the first direction L. The blood outlet opening 46 that extends through the dilator body 34 proximal to the blood inlet hole 42. The blood inlet hole 42 and the blood outlet opening 46 are in fluid communication with each other such that when the blood inlet hole 42 enters the vessel 13, blood from the vessel 13 will enter the blood inlet hole 42 and exit the blood outlet opening 46 into the blood pulsation indicator 50, to thereby indicate that the blood inlet hole 42 has entered the vessel 13, as further explained below. In the illustrated embodiment, the blood inlet and outlet openings 42 and 46 extend into the guide channel 38 such that blood entering the blood inlet hole 42 will travel through the guide channel 38, around the guidewire 14, and out the blood outlet opening 46 into the blood pulsation indicator 50. It should be appreciated, however, that in some embodiments, the guide channel 38 and the channel through which the blood flows can be separate and distinct from each other, as desired. In particular, the guide channel 38 is sized to have a tight fit around the guidewire.

As shown in FIGS. 2-5, the blood pulsation indicator 50 is used to locate the puncture. More specifically, the blood pulsation indicator 50 is configured to be responsive to presence of pulsatile blood flow inside the dilator 10 when the inlet hole is located inside the vessel. As shown, the blood pulsation indicator 50 includes a flexible barrier 60 attached to the elongated dilator 10 and overlying the outlet opening 46. Configured this way, the flexible barrier 60 and the outer surface 39 proximate the outlet opening 46 at least partially defines an internal volume IV. When the elongated dilator 10 is inserted into the puncture 12 of the blood vessel 13, blood flows into the inlet opening 42 through the outlet opening 46 into the internal volume IV such that, pulsations in the blood flow cause the flexible barrier 60 to pulse, thereby generating a visual and tactile indication of presence of the inlet opening 42 in the blood vessel 13.

The flexible barrier 60 may be formed from a polymeric material that is flexible, yet durable enough to withstand pulsatile flow. For example, the flexible barrier may be polyvinylchloride, polyethylene, polyurethane, polyamides, and/or copolymer thereof. The flexible barrier can be planar shape, a sleeve, or form part of pocket, pouch, bag or other structure that can enclose a fluid.

The flexible barrier 60 may overlie the outlet opening to form an internal volume. In the illustrated embodiment, as shown in FIG. 3, attachment members 62 and 64 secure the flexible barrier in place on the dilator body 34. In one example, the flexible barrier may only overlie a portion of the dilator body 34. In other configurations, the flexible barrier may be in form of a sleeve that surrounds an entirety of the dilator body 34 proximate the outlet opening 46.

The blood pulsation indicator 50 may have configurations other than what is specifically illustrated. For example, in one alternative embodiment, the flexible barrier may be part of a flexible container that is attached to the elongated dilator. For instance, the flexible container may be flexible bag or bladder attached to the dilator.

In addition, the dilator may further comprise a handle member disposed on the elongated dilator. In such an embodiment, the elongated dilator includes a port disposed in the outlet opening 46. The flexible barrier is attached to the handle member such that the port extends from the elongated dilator to the flexible barrier.

Now, in reference to FIGS. 2-5, the elongated dilator 10 can further include a plurality of depth markings 54 spaced from each other along the first direction L between the inlet opening 42 and outlet opening 46. The depth markings 54 can be used to visually note the depth or otherwise the location of the puncture site 12 of the vessel 13 when the elongated dilator 10 has been positioned within the vessel. In the illustrated embodiment, the depth markings 54 are numbers on the dilator body 34. It should be appreciated, however, that the depth markings 54 can have other configurations as desired. For example, the depth markings can be configured as symbols as desired. The depth markings 54 can be used to locate the puncture site 12. That is, after a position of the puncture site 12 has been located with the blood inlet hole 42, a position of a first visible marking of the plurality of depth markings 54 on the dilator that is adjacent the patient's skin can be noted when the blood flows. Therefore, the position of the puncture site 12 can be known for the remainder of the procedure. The noted first marking can be noted with a sticker that is placed directly on the patient's skin as desired. It should be appreciated, however, that the first depth marking can be noted using other configurations as desired. For example, the first depth marking can be noted with a tag, card, clip, etc. In an alternative embodiment, the depth markings of this embodiment can either be used alone or in combination with the radiopaque markers.

The puncture sealing system 2 can further include an access sheath 118 that is also configured to be moved along the guidewire 14 toward the puncture site 12 and into the vessel 13 so as to further dilate the puncture site 12 and subsequently provide access to the vessel 13. The access sheath 118 can then receive a vascular sealing device 190 that is configured to seal the puncture site 12. It should be appreciated, however, that the system can include additional dilators that have cross-sectional diameters that are different (e.g. greater) than the diameter of the locating dilator 10 but less than that of the access sheath 118 so that the puncture site 12 can be gradually dilated and prepared for the access sheath 118. Both the locating dilator 10 and the access sheath 118 include respective depth markings that are configured to aid in locating the puncture site 12, as will be further described below.

Now referring to FIG. 6, the access sheath 118 includes a sheath body 160 that is elongate along the first direction L and a sheath dilator 164 that is coupled within an access channel 168 of the sheath body 160. The access channel 168 extends through the sheath body 160 from a proximal end through to a distal end of the sheath body 160 and is configured to provide an access path to the puncture site 12 after the sheath dilator 164 has been removed from the access channel 168. The access sheath 118, like the elongated dilator 10, is configured to be moved along the guidewire 14 toward the puncture site 12 such that the distal end of the access sheath 118 enters the vessel 13.

With continued reference to FIG. 6, the access sheath 118 further includes a plurality of depth markings 172 spaced from each other along the first direction L on the sheath body 160. The depth markings 172 correspond to the depth markings 54 on the elongated dilator 10 such that as the access sheath 118 is inserted into the vessel 13 the location of the distal end of the access sheath 118 relative to the puncture site 12 can be known because of the depth markings 172. In the illustrated embodiment, the depth markings 172 are numbers. It should be appreciated, however, that the depth markings 172 can have other configurations as desired so long as they somehow correspond to the depth markings 54. The depth markings 172 can be used to position the sheath body 160 so that a closure device 190 that is to be moved into the access channel 168 will be properly positioned for sealing of the puncture site 12. For example, the sheath body 160 can be positioned such that a first marking of the depth markings 172 that corresponds to the noted first visible marking on the dilator 10 is the first visible marking on the access sheath 118. When the first visible marking of the access sheath 118 corresponds to the noted first visible marking on the elongated dilator 10, the appropriate amount of sheath body 160 will be disposed within the vessel 13. It should be appreciated, however, that in some embodiments, the depth markings 172 can be placed on the closure device 190 rather than the sheath body 160.

As shown in FIG. 6, a distance d between a distal end of the access sheath 118 and a first marking of the plurality of depth markings 172 may generally correspond to the distance between the distal end of the puncture dilator and its first marking of the plurality of markings.

Now referring to FIGS. 7-9, the guide wire 14 can be inserted through the puncture site 12 and into the vessel 13 such that a portion of the guidewire 14 protrudes from the vessel. Once the guidewire 14 is positioned, a proximal end of the guidewire 14 can be inserted into the distal end of the elongated dilator 10. As shown in FIG. 8, the elongated dilator 10 can then be moved along the guidewire 14 until the distal end of the elongated dilator 10 and the blood inlet hole 42 enter the vessel 13 such that blood flows into the inlet hole 42 and into the blood pulsation indicator 50, causing the flexible barrier 60 to pulsate, thereby indicating the inlet hole 42 is inside the vessel tract. In this scenario the blood within the patient will have a new avenue available to flow within, once the blood begins to flow through the inlet opening 42 and out the outlet opening 46 it will be caught within a flexible barrier 60. Once the dilator 10 has been inserted into the circulatory track the flexible barrier 60 will begin to mimic the flow rate and pressure inherent within the vessel. This will cause the flexible barrier 60 to pulsate and will supply the practitioner with both a visual and tactile indicator for when the dilator 10 is within the vessel. From there a slow removal of the dilator 10 is performed, from this action the depth of the puncture can be ascertained, which is when the pulsation of the flexible barrier 60 ceases. Once the pulsations have ceased the depth can be collected according to the depth marking visible just above skin level of the patient. In other words, the position of the puncture site 12 can be confirmed via feedback of blood flow entering the blood pulsation indicator 50 by alternatingly inserting and retracting the elongated dilator 10. As shown in FIG. 7, after the position of the puncture site 12 has been located, a first visible marking 54 a of the dilator 10 can be noted. That is a first visible marking 54 a that is adjacent the patient's skin can be noted. It should be appreciated, that in some embodiments, the elongated dilator 10 can be positioned over the guidewire 14 prior to the guidewire being inserted into the vessel 13.

As shown in FIG. 10, after the elongated dilator 10 has been removed from the guidewire 14 and any subsequent dilators have been removed, the access sheath 118 can be moved along the guidewire 14 toward the puncture site 12 such that the distal end of the access sheath 118 enters the vessel 13 through the puncture site 12. In particular, the proximal end of the guidewire 14 is inserted into the distal end of the sheath dilator 164. And then the sheath body 160 and sheath dilator 164 can be moved together along the guidewire 14 toward the puncture site 12. Once inserted, the sheath dilator 164 can be pulled proximally such that the sheath dilator 164 is removed from the access channel 168.

After the sheath dilator 164 has been removed, a vascular closure procedure can be performed through the access channel 168. Therefore, a closure device 190 can be moved into the access channel 168 until a distal portion 192 (e.g. at least a portion of a toggle 194) of the closure device 190 is distal to the distal end of the sheath body 160. As shown in FIG. 5C the access sheath 118 can then be moved such that a first visible marking 172 a of the sheath body 160 that is visible adjacent the patient's skin corresponds with the noted first visible marking 54 a of the elongated dilator 10. It should be appreciated, that the closure device 190 can be moved into the access channel 168 either prior to or after the positioning of the access sheath 118 such that the first visible marking 172 corresponds to the noted depth marking 54. When the access sheath 118 is properly positioned, the closure device 190 will be positioned such that the sealing procedure can be completed. It should be appreciated, that while in the illustrated embodiment, in some embodiment's the depth markings 172 are on the sheath body 160, the depth markings can be on the closure device 190, as desired. Furthermore, it should be appreciated, that in such embodiments, the access sheath 118 can be pulled completely out of the vessel 13 when the closure device 190 is properly positioned.

While the foregoing description and drawings represent the preferred embodiment of the present invention, it will be understood that various additions, modifications, combinations and/or substitutions may be made therein without departing from the spirit and scope of the invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the invention may be embodied in other specific forms, structures, arrangements, proportions, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. One skilled in the art will appreciate that the invention may be used with many modifications of structure, arrangement, proportions, materials, and components, which are particularly adapted to specific environments and operative requirements without departing from the principles of the invention. In addition, features described herein may be used singularly or in combination with other features. For example, features described in connection with one component may be used and/or interchanged with features described in another component. The presently disclosed embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and not limited to the foregoing description.

It should also be noted that the use of the present invention may occur at different points of the surgical procedure then specified previously. For instance, rather than being utilized before the introduction of the closure device it may instead be used to ascertain the depth of the initial incision prior to the surgical procedure being fully performed. 

What is claimed:
 1. A method for locating a puncture in a blood vessel of a patient, the method comprising: inserting a distal end of a dilator over a proximal end of a guidewire that extends out of the puncture in the blood vessel; and moving the dilator along the guidewire in a distal direction until blood in the blood vessel flows through an inlet opening of the dilator and into an internal volume at least partially defined by a flexible barrier carried by the dilator, such that, the flexible barrier repeatedly pulses in response to pressure pulsations of blood in the blood vessel, thereby generating a visual and tactile indication of presence of the inlet opening in the blood vessel.
 2. The method of claim 1, inserting a guidewire through the puncture into the blood vessel so that the distal end of the guidewire is inside the blood vessel and the guidewire extends out of the puncture.
 3. The method of claim 1, wherein the dilator has a plurality of markings, and further comprising: retracting the dilator in a proximal direction along the guidewire until the flexible barrier no longer pulses; and noting a marking of the plurality of markings on the dilator that is adjacent to a surface of a patient's skin when flexible barrier no longer pulses.
 4. The method of claim 3, wherein the plurality of markings on the dilator are a first plurality of markings, and the marking is a noted first marking, wherein the method further comprises: removing the dilator from the puncture along the guidewire; moving an access sheath along the guidewire toward the puncture, the access sheath defining a distal end, a proximal end, and a second plurality of markings disposed between the distal end and the proximal end of the access sheath, the second plurality of markings corresponding to the first plurality of markings of the dilator; and further moving the access sheath along the guidewire until the distal end of the access sheath enters the blood vessel and until a marking of the second plurality of markings on the access sheath that corresponds to the noted first visible marking on the dilator is a first visible marking of the access sheath that is adjacent to the patient's skin.
 5. The method of claim 1, after moving the dilator along the guidewire, performing a surgical procedure in the blood vessel.
 6. The method of claim 5, comprising the steps of, prior to performing the surgical procedure in the blood vessel includes: inserting a procedural sheath into puncture; inserting a surgical device into the procedural sheath; and removing the surgical device and procedural sheath from the blood vessel.
 7. The method of claim 1, wherein the dilator includes a proximal end spaced from the distal end along a central axis and an outer surface, wherein the outer surface of the dilator defines an outer cross-sectional dimension that is substantially perpendicular to the central axis, wherein the outer cross-sectional dimension is at least 2.50 mm.
 8. The method of claim 1, wherein the in pulsations in the blood flow cause the flexible barrier to pulse outwardly, thereby generating the visual and tactile indication of presence of the inlet opening in the blood vessel.
 9. A method for locating a puncture in a blood vessel of a patient, the method comprising: inserting a distal end of a dilator over a proximal end of a guidewire that extends out of the puncture of the blood vessel; and moving the dilator along the guidewire in a distal direction until blood in the blood vessel flows through an inlet opening of the dilator and into an internal volume at least partially defined by a blood pulsation indicator overlying an outlet opening of the dilator, whereby the blood pulsation indicator repeatedly pulses in response to pressure pulsations of blood in the blood vessel, thereby generating a visual and tactile indication of presence of the inlet opening in the blood vessel.
 10. The method of claim 9, inserting a guidewire through the puncture into the blood vessel so that the distal end of the guidewire is inside the blood vessel and the guidewire extends out of the puncture.
 11. The method of claim 9, wherein the dilator has a plurality of markings, and further comprising: retracting the dilator in a proximal direction along the guidewire until the blood pulsation indicator no longer pulses; and noting a marking of the plurality of markings on the dilator that is adjacent to a surface of a patient's skin when flexible barrier no longer pulses.
 12. The method of claim 11, wherein the plurality of markings on the dilator are a first plurality of markings, and the marking is a noted first marking, wherein the method further comprises: removing the dilator from the puncture along the guidewire; moving an access sheath along the guidewire toward the puncture, the access sheath defining a distal end, a proximal end, and a second plurality of markings disposed between the distal end and the proximal end of the access sheath, the second plurality of markings corresponding to the first plurality of markings of the dilator; and further moving the access sheath along the guidewire until the distal end of the access sheath enters the blood vessel and until a marking of the second plurality of markings on the access sheath that corresponds to the noted first visible marking on the dilator is a first visible marking of the access sheath that is adjacent to the patient's skin.
 13. The method of claim 9, after moving the dilator along the guidewire, performing a surgical procedure in the blood vessel.
 14. The method of claim 13, comprising the steps of, prior to performing the surgical procedure in the blood vessel includes: inserting a procedural sheath into puncture; inserting a surgical device into the procedural sheath; and removing the surgical device and procedural sheath from the blood vessel.
 15. The method of claim 9, wherein the dilator includes a proximal end spaced from the distal end along a central axis and an outer surface, wherein the outer surface of the dilator defines an outer cross-sectional dimension that is substantially perpendicular to the central axis, wherein the outer cross-sectional dimension is at least 2.50 mm.
 16. The method of claim 9, wherein the in pulsations in the blood flow cause the blood pulsation indicator to pulse outwardly, thereby generating the visual and tactile indication of presence of the inlet opening in the blood vessel.
 17. A method for locating a puncture in a blood vessel of a patient, the method comprising: inserting a guidewire through the puncture into the blood vessel so that a distal end of the guidewire is inside the blood vessel and the guidewire extends out of the puncture; inserting a distal end of a dilator over a proximal end of the guidewire; and moving the dilator along the guidewire in a distal direction until blood in the blood vessel flows through an inlet opening of the dilator and into an internal volume at least partially defined by a blood pulsation indicator carried by the dilator, such that the blood pulsation indicator repeatedly pulses in response to pressure pulsations of blood in the blood vessel, thereby indicating presence of the inlet opening in the blood vessel.
 18. The method of claim 17, wherein the dilator has a plurality of markings, and further comprising: retracting the dilator in a proximal direction along the guidewire until the blood pulsation indicator no longer pulses; and noting a marking of the plurality of markings on the dilator that is adjacent to a surface of a patient's skin when flexible barrier no longer pulses.
 19. The method of claim 18, wherein the plurality of markings on the dilator are a first plurality of markings, and the marking is a noted first marking, wherein the method further comprises: removing the dilator from the puncture along the guidewire; moving an access sheath along the guidewire toward the puncture, the access sheath defining a distal end, a proximal end, and a second plurality of markings disposed between the distal end and the proximal end of the access sheath, the second plurality of markings corresponding to the first plurality of markings of the dilator; and further moving the access sheath along the guidewire until the distal end of the access sheath enters the blood vessel and until a marking of the second plurality of markings on the access sheath that corresponds to the noted first visible marking on the dilator is a first visible marking of the access sheath that is adjacent to the patient's skin.
 20. The method of claim 19, wherein the in pulsations in the blood flow cause the blood pulsation indicator to pulse outwardly, thereby generating the visual and tactile indication of presence of the inlet opening in the blood vessel. 